‘Halos’ discovered on Mars widen time frame for potential life

Lighter-toned bedrock that surrounds fractures and comprises high concentrations of silica--called "halos"--has been found in Gale crater on Mars, indicating that the planet had liquid water much longer than previously believed.

Lighter-toned bedrock that surrounds fractures and comprises high concentrations of silica--called "halos"--has been found in Gale crater on Mars, indicating that the planet had liquid water much longer than previously believed.